The retail fruit industry has dictated that fruit especially citrus fruit has to be coated in wax prior to sale. Fruit growers have thus inherited the problem to efficiently coat fruit with wax. One way of coating fruit with wax is to provide a cloud of particles of liquid wax and to rotate the fruit past the cloud thereby ensuring that the whole periphery of the fruit is covered with wax. The fruit is often rotated on cylindrical brushes which in turn become coated with wax and serve to further ensure a comprehensive covering of the periphery of the fruit.
The cloud of liquid wax is produced by an applicator head assembly that usually includes a spinning distributor onto which the liquid wax is passed to be centrifugally ejected in a cloud of small particles.
The head assemblies described above have proved inefficient for a number of reasons. In some cases, the wax is distributed in a non-uniform manner meaning that the fruit is unevenly coated. In other situations the applicator clogs with wax when switched off and has to be frequently cleaned. The equipment often has a limited life span with frequent need for maintenance. The final problem with equipment of the kind described above is wastage of comparatively expensive wax.
It is these problems that have brought about the present invention.
According to one aspect of the present invention there is provided a head assembly adapted to be connected to the output shaft of a motor, the head assembly in use providing a cloud of liquid wax for coating foodstuffs, the head assembly comprising a collector means arranged to be coaxially attached to the output shaft of the motor, a dispensing shroud attached to the collector means to surround the collector means with the internal wall of the shroud spaced radially from the collector means, a housing adapted to be attached to the motor and adapted to be coupled to a source of liquid wax, a delivery tube extending from the housing to the collector means within the shroud, the delivery tube having an aperture at one end being positioned in close proximity to the collector means whereby in use liquid wax flows down the delivery tube to form a bead on the collector means to be centrifugally dispensed against the internal wall of the shroud and to run down the shroud to be expelled as a mist or cloud of wax particles.
Preferably the housing is adapted to be coupled to a source of compressed gas and the underside of the housing is provided with a plurality of equally spaced gas jets so that in use gas under pressure expels from the underside of the housing against the exterior of the shroud to control the shape and configuration of the mist or cloud of wax particles.
In a preferred embodiment, the collector means is a stepped shaft that is coaxially attached to the output shaft of the motor. Preferably, the stepped shaft has a cylindrical portion on which the bead of wax is formed, the cylindrical portion merging into a frusto conical portion that is attached to a disc that extends radially to join the collector means to the interior of the shroud.
The interior of the shroud may be provided with a plurality of longitudinally extending grooves down which the wax flows in use to be centrifugally dispersed from the base of the shroud.
In a preferred embodiment, the exit of the delivery tube is approximately half a millimeter from the collector means. Preferably, the collector means and shroud rotate at speeds of between 2000 and 5000 revolutions per minute.